BOWLING GREEN, Ky. (AP) _ Marquel Blackwell passed for three first-half touchdowns to lead South Florida to a 21-6 victory over Western Kentucky on Saturday night.

Blackwell, a freshman, completed 12 of 16 passes in the first half for 151 yards as the Bulls (2-1) did all their scoring in the opening half and let their defense hold the Hilltoppers in check in the second half.

South Florida scored first on a 48-yard TD pass from Blackwell to Scott McCready with 10 minutes left in the opening quarter.

Western Kentucky (2-1) answered with a 64-yard drive capped by a 2-yard touchdown run by quarterback Jason Michael. The extra point was blocked.

Blackwell struck again late in the first quarter, firing a 25-yard scoring pass to Deandrew Rubin to give South Florida a 14-6 lead.

Blackwell's third touchdown was a 6-yarder to Rubin in the second quarter to culminate a 73-yard, nine-play drive.

Western Kentucky threatened in the fourth quarter, marching to the South Florida 13 before the drive ended when Michael's pass fell incomplete in the end zone.